Chemical apparatus



April 25, 1944.

J. J. BRADLEY CHEMICAL APPARATUS Filed Oct. 51, 1941 INVENTOR ATTORNEY Patented Apr. 25, 1944 CHEMICAL APPARATUS John J. Bradley, Cranford, N. J asslgnor to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware Application October 31, 1941, Serial No. 417,333

3 Claims. (Cl. 257-93) This invention relates to chemical apparatus and is particularly directed to improvements in rotary heat exchangers particularly adapted to cooling hot sodium sulfide and to cooling or heating like chemicals subject to oxidation at ele vated temperature.

Sodium sulfide is commonly manufactured by the reduction of sodium sulfate with coal, coke, or other reducing media. The reaction is a high temperature one. If the hot sodium sulfide is discharged in the atmosphere, as is frequently the case in connection with rotary furnaces, a reversal of the reaction takes place and sodium sulfate is formed. While the amount of sulfate thus formed normally is small nevertheless it interferes with and complicates subsequent processing of the crude sodium sulfide.

It is an-object of the present invention to avoid the disadvantages of the prior art by providing simple and effective apparatus whereby the sodium sulfide and like chemicals may be cooled or heated out of contact with air. It is another object of. the invention to provide means for excluding air from a' rotary heat exchanger. It is another object to provide such means as will not be warped or buckled or thrown out of alignment by hot material in the heat exchanger.

ther objects will appear hereinafter.

These objects are'accomplished by the following invention, an embodiment of which is illustrated in the accompanying, drawing in which Figure I is a section taken in elevation, Figure 11 is a section taken along lines 2-2 Figure I, and Figures III and IV are enlarged detail views of parts of Figure I.

As best seen in Figure I, the invention is concerned with rotary coolers of the axial charging and discharge type. Such coolers include a cylindrical shell I and suitable end closures 2 and 2' each of which is provided with an axial port 3 and 3'. Attached to each of these ports is a hollow trunnion 4i and t which serves as charging and discharging means as well as means for rotatably supporting the cooler in a horizontal position. In

this position the cooler is adapted to be rotated about a horizontal axis while partially submerged in a cooling bath.

As best shown in Figure III, I have provided axially reciprocal. closure-means for the charg-' ing and discharge ports. In order to close they charging port I providev the closure 5 and means for thrusting it axially into closing position with respect to the .hollow trunnion 4, the innermost edge of which is bevelled at 6 complementary with a corresponding beve1 l on the closure plate 5.

On the face of the closure 5 are provided correspondingly bevelled lugs 8 arranged about the periphery of the plate 5 which act to center the closure plate 5 in the charging opening with thecomplementary bevelled faces 6 and l in feeling contact.

The mechanism for operating the closure 5 consists of a long axially disposed shaft 9, supporting means I!) and Ill, and an actuating cylinder II. The latter may be of any conventional design and provided with suitable valves (not shown) for causing the piston I! to move the closure plate 5 to and from closing position, as desired.

The supports l0 and it are specially designed in view of the rigorous conditions obtain ng in the rotary cooler when freshly charged with hot sulfide. In order to prevent these rigorous conditions from warping the supports and throwing the shaft 9 out of line or causing it to bind in the journals l3 and i3 I have provided means for cooling the journals and the supporting legs It and i i. To this end the supports are constructed in the nature of tripods, each leg of which is hollow and communicates between-the exterior of the cylindrical shell 8 to the interior of the hollow trunnion l3 and Hi. This is best seen in Figure II where the supports it! and' M are shown to communicate through the apertures with the exterior of the shell 5. About each of these apertures are located cups It, so located as to scoop up water in the rotation of the cooler. In this manner Cooling water is continuously circulated in and out of the supports Hi and it and in and around inside the journals l3 and it. Thus warping and binding of the supports is avoided.

The closure means for the discharge port is located exteriorly. It consists of the closure plate ll which is reciprocally mounted on the shaft Q so that it may be forced axially into engagement with the outer edge of trunnion 4' which is bevelled at I8 complementary with the bevel as on the closure plate H in order to provide an airtight seal. For the same purpose the closure plate W is provided with a stufiing box 28 about its engagement on the shaft 8. The closure plate ll is actuated by the piston 29 reciprocating in the cylinder 22. The piston rod 23 is provided with a crosshead M which is rigidly connected to the closure plate W by means of the rods 25. These rods are guided in apertures 26 in extended portions of cylinder head 27 of cylinder ii and in apertures 28 in extended portions of cylinder head 29 of cylinder 22.

The closure operating mechanism is forced in axial alignment with the rotary cooler by means tight 2 d1 angle a which the cylinder head 21 with the iiangs 8| on the outermost edge oi the trunnion 4'. suilicient space is thus tors the opening and closing or'closure plate il-anddischarle of material. Y

The pistons I: and ii maybe actuated by air or other fluid, connections being made with an external source through any suitable rotatin closure of, the charging and discharge ports. By

the particular combination of an interior closure at least one tripod composed of hollow members, and means for introducing cooling fluid into said a hollow. members.

for the charging port and an exterior closure for U the dischargingfport I have, avoided all conflict with the usualscrews required for charging and discharging rotary, coolers oi this type. 7

While I have illustrated my invention: with reference to one particular embodiment thereof it will be understood that variations maybe made without departing from the spirit and scopeof the invention;

I claim:

' 1. Ina rotary cooler provided with axial'charg-,

ing and discharge ports the combination comprising a closure means located interiorly ofesaid cooler, means for causing said closuremeans to move axially into closingposition with respect to one of said, ports, said means comprising an axially disposed shaft connecting said' closure me'answith: closure operatorm'eans disposed ex- -teriorly oi-said cooler and so arranged that the shaft extendsthrough the other port, means for supporting said shaft in axial position comprising 2. In a rotary cooler adapted to rotate partially submerged in a cooling bath the combination with axial charging and discharging ports in said cooler of closure means located interiorly of said cooler, means for causing said closure means to move axially into closing position with respect to one of said ports, said. means comprising an axially disposed shait connecting said closure means with closure operator means disposed exteriorly of said cooler and so arranged that the shalt extends through the other port, means for supporting said shaft in axialposition comprising at least one tripod composed of hollow members, and means for introducing cooling fluid into said hollow members, said last named means'comprising cups on the surface oi. said cooler in communication with said hollow members and so arranged as to scoop up cooling liquid in the rotation of said cooler. .v

3.. In a rotary heat exchanger having axial inlet and outlet ports the combination -oi! closure means disposed interiorly of said heat exchanger, means for supporting said closure i'or axial movement to and from the. inlet port including an axial reciprocable shaft extending from said closure means through said outlet port to a point exterior of said heat exchanger, a second closure means disposed exteriorly of saidheat exchanger. and journaled on said shaft and being free to move axially independently of said shaft, and means independently operable foraxially moving said closure means to and from said ports.

' i p JOHN J. BRADLEY. 

